Use clock_gettime instead of base::TimeTicks::Now() in QUIC

net/quic/platform/impl/quic_chromium_clock.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/quic/platform/impl/quic_chromium_clock.h"
 
+#if defined(OS_IOS)
+#include <time.h>

[ianswett, 2017/05/10 10:44:13]

nit: Should this be indented, like it is below?

[Ryan Hamilton, 2017/05/10 13:17:27]

I don't think so, because #includes are not indented.

+
+#include "base/ios/ios_util.h"
+#endif
+
 #include "base/memory/singleton.h"
 #include "base/time/time.h"
 
 namespace net {
 
 QuicChromiumClock* QuicChromiumClock::GetInstance() {
   return base::Singleton<QuicChromiumClock>::get();
 }
 QuicChromiumClock::QuicChromiumClock() {}
 
 QuicChromiumClock::~QuicChromiumClock() {}
 
 QuicTime QuicChromiumClock::ApproximateNow() const {
   // At the moment, Chrome does not have a distinct notion of ApproximateNow().
   // We should consider implementing this using MessageLoop::recent_time_.
   return Now();
 }
 
 QuicTime QuicChromiumClock::Now() const {
-  return QuicTime(base::TimeTicks::Now());
+#if defined(OS_IOS)
+  if (base::ios::IsRunningOnIOS10OrLater()) {
+    struct timespec tp;
+    clock_gettime(CLOCK_MONOTONIC, &tp);
+    return CreateTimeFromMicroseconds(tp.tv_nsec / 1000);

[kapishnikov, 2017/05/10 15:25:38]

Should it be:
return CreateTimeFromMicroseconds(tp.tv_sec * 1000000 + tp.tv_nsec / 1000)

Otherwise, the time will reset every second.

[Ryan Hamilton, 2017/05/10 17:05:56]

Done.

+  }
+#endif
+  return CreateTimeFromMicroseconds(base::TimeTicks::Now().ToInternalValue());

[ianswett, 2017/05/10 11:40:36]

As mentioned in the thread, Ideally we'd update base/time/time_mac.cc to
optimize other calls, such as the call in
NetworkActivityMonitor::IncrementBytesReceived

[Ryan Hamilton, 2017/05/10 13:17:27]

That's beyond the scope of this CL, but I'll talk with base OWNERS about this.

 }
 
 QuicWallTime QuicChromiumClock::WallNow() const {
   return QuicWallTime::FromUNIXMicroseconds(base::Time::Now().ToJavaTime() *
                                             1000);
 }
 
 }  // namespace net